The vagus nerve, also known as cranial nerve X, is the longest and most expansive cranial nerve in the body. It stretches from the brainstem to the abdomen, connecting to the heart, lungs, digestive system, and many other organs. This vital nerve is often called the “wandering nerve” because of its extensive reach and diverse functions.
The vagus nerve plays a key role in managing essential body functions, including digestion, heart rate, inflammation, and breathing. It also helps the body recover from stress by activating the rest-and-digest response and is deeply intertwined with mental and emotional well-being.
Why the Vagus Nerve Matters
Recent research shows that the vagus nerve has powerful anti-inflammatory properties. For example, it reduces the production of inflammatory chemicals (cytokines), such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8). These cytokines play a role in the body’s immune response, but their overproduction is linked to chronic diseases like heart disease, autoimmune disorders, and depression. By inhibiting these chemicals, the vagus nerve helps reduce inflammation and supports overall health.
Additionally, the vagus nerve works through the cholinergic anti-inflammatory pathway (CAP) by releasing acetylcholine, a neurotransmitter that interacts with immune cells to suppress the production of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α).
Another key mechanism is the splenic sympathetic anti-inflammatory pathway, in which the vagus nerve indirectly influences the spleen via the sympathetic nervous system. This leads to the release of norepinephrine, which interacts with immune cells to suppress excessive inflammation by reducing pro-inflammatory cytokines.
Together, these interconnected mechanisms highlight how essential the vagus nerve is for maintaining balance and health in the body.
The vagus nerve doesn’t just control physical functions like digestion and heart rate – it also plays a big role in social connection and emotional well-being. According to Polyvagal Theory, the vagus nerve helps us feel safe in our environment and relationships, making it easier to connect with others and build trust.
A key part of this is the ventral vagal complex, which helps regulate facial expressions, tone of voice, and eye contact. These are all important for effective communication and feeling comfortable around people. When the ventral vagal complex is active, it helps you feel calm, socially engaged, and emotionally balanced.
In simple terms, the vagus nerve – especially the ventral vagal complex—acts like a built-in social safety system, helping your body and mind relax so you can form healthy relationships and manage stress better.
How to Measure Vagus Nerve Health
Vagal tone measures how effectively the vagus nerve regulates bodily functions. It is most commonly assessed using heart rate variability (HRV), which evaluates the variation in time between heartbeats:
- High vagal tone: Indicates effective stress regulation, lower inflammation, and better overall resilience.
- Low vagal tone: Reflects higher stress, increased inflammation, and greater susceptibility to chronic diseases.
Emerging tools, including wearable devices such as the Oura ring and Whoop watch, and smartphone apps, allow individuals to monitor HRV and track improvements in their vagal tone through lifestyle interventions. The Apollo wearable does not track heart rate variability (HRV) directly. Instead, it delivers gentle vibrations designed to improve HRV by promoting relaxation and balance in the autonomic nervous system. Apollo suggest that the wearable can lead to significant increases in HRV.
How to Stimulate the Vagus Nerve
Improving vagus nerve function doesn’t require complex interventions. There are many simple and effective techniques:
- Deep Breathing: Slow, diaphragmatic breathing activates the parasympathetic nervous system and reduces stress. Consistent practice can significantly improve vagal tone.
- Singing or Humming: These activities engage the vocal cords, stimulating the vagus nerve and promoting relaxation. Chanting or reciting mantras may also have similar effects.
- Cold Exposure: Splashing cold water on the face, immersing the face in cold water, or taking cold showers can stimulate the vagus nerve and improve mood and energy levels.
- Social Connection: Positive social interactions, acts of kindness, and expressing gratitude enhance vagal activity. These practices also support emotional well-being and resilience.
- Healthy Diet: Probiotic-rich foods like yogurt, kefir, and sauerkraut support gut health, which is intricately linked to the vagus nerve through the gut-brain axis. Fiber-rich foods also play a role in maintaining this connection.
- Laughter: Laughter, especially in social settings, engages the vagus nerve and reduces stress. Incorporating humor and joy into daily life can have lasting health benefits.
Medical and Alternative Techniques
For those seeking more specialized approaches, these advanced methods offer targeted benefits:
- Auricular Acupuncture: This technique stimulates the auricular branch of the vagus nerve located in the ear. Studies show it can reduce inflammation, enhance relaxation, and improve overall vagal function.
- Transcutaneous Vagus Nerve Stimulation (taVNS):Non-invasive devices deliver mild electrical stimulation to the vagus nerve through the skin, particularly around the ear or neck. These tools have shown promise in treating migraines, pain, and mood disorders.
- Implantable Devices: FDA-approved devices deliver electrical signals to the vagus nerve, offering effective treatment for conditions like epilepsy, depression, and other chronic diseases.
Why Social Safety Matters
The vagus nerve plays a vital role in helping us feel safe and connected in social situations. Smiling, positive interactions, and calm environments activate the ventral vagal complex, fostering trust and emotional security.
The Polyvagal Theory underscores this connection by explaining how the vagus nerve responds to safety cues and supports social engagement. For example, a calm voice, gentle eye contact, or a friendly smile can activate the vagus nerve, reduce stress, and promote well-being.
The Future of Vagus Nerve Research
Scientists are uncovering new roles for the vagus nerve in health and disease. For example, vagus nerve stimulation may lead to breakthroughs in treating:
- Alzheimer’s disease and other neurodegenerative conditions, potentially by reducing amyloid accumulation and improving cognition.
- Post-traumatic stress disorder (PTSD) and mood disorders, by regulating stress responses and enhancing emotional resilience.
- Chronic pain syndromes and inflammatory diseases, by modulating pain signals and reducing systemic inflammation.
In addition, researchers are exploring the vagus nerve’s broader impact on the gut-brain axis, investigating how its activity influences gut microbiota, immune system function, and mental health. These insights could lead to innovative therapies for conditions like irritable bowel syndrome (IBS), anxiety, and even metabolic disorders.
Emerging areas of interest include:
- Longevity Research: Investigating how enhanced vagus nerve function supports healthier aging and reduces the risk of age-related diseases.
- Immune Modulation: Understanding its role in reducing autoimmune and inflammatory conditions.
- Personalized Therapies: Developing treatments tailored to individual health profiles, leveraging biomarkers and genetic insights.
- Mental Health Integration: Exploring how vagus nerve stimulation can support broader mental health treatments, including anxiety, depression, and even addiction recovery.
- Neuroplasticity and Recovery: Researching how vagus nerve stimulation may enhance brain plasticity, potentially improving outcomes after strokes, traumatic brain injuries, or other neurological conditions.
These discoveries highlight the vagus nerve’s potential to transform how we approach chronic disease, mental health, and overall well-being.
Conclusion
The vagus nerve is a vital connection between the brain and body. It regulates essential functions like digestion, heart rate, and inflammation while supporting emotional well-being. By improving vagus nerve activity, you can reduce stress, enhance resilience, and improve your overall health.
Simple practices like deep breathing, laughter, and positive social connections can make a significant difference. Start small and stay consistent. Over time, you’ll experience the benefits of a healthier vagus nerve in both your body and mind.
I believe in making time for the small joys in life, and one of my favorite pastimes is enjoying a relaxing picnic in nature. Whether it’s under a shady tree or beside a sparkling stream, these moments of connection with nature and loved ones are rejuvenating – much like supporting the health of your vagus nerve.
Note: This article is based on the doctoral research paper Demystifying the Vagus Nerve: Auricular Acupuncture and Other Viable Interventions, authored by Dr. Mary Clark, DACM, LAc, at Pacific College of Health and Science (formerly known as Pacific College of Oriental Medicine).
References
- Arneth, B. M. (2018). Gut–brain axis biochemical signaling from the gastrointestinal tract to the central nervous system: Gut dysbiosis and altered brain function. Postgraduate Medical Journal, 94(1114), 446-452.
- Bellinger, D., & Lorton, D. (2018). Sympathetic nerve hyperactivity in the spleen: causal for nonpathogenic-driven chronic immune-mediated inflammatory diseases (IMIDs)? International Journal of Molecular Sciences, 19(4), 1188.
- Bertrand, D., Lee, C. H., Flood, D., Marger, F., & Donnelly-Roberts, D. (2015). Therapeutic potential of α7 nicotinic acetylcholine receptors. Pharmacological Reviews, 67(4), 1025-1073.
- Bonaz, B., Sinniger, V., & Pellissier, S. (2016). Anti‐inflammatory properties of the vagus nerve: potential therapeutic implications of vagus nerve stimulation. The Journal of Physiology, 594(20), 5781-5790.
- Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus nerve as modulator of the brain–gut axis in psychiatric and inflammatory disorders. Frontiers in Psychiatry, 9, 44.
- Bremner, J.D., Gurel, N.Z., Wittbrodt, M.T., Shandhi, M.H., Rapaport, M.H., Nye, J.A., Pearce, B.D., Vaccarino, V., Shah, A.J., Park, J., Bikson, M. and Inan, O.T., 2020. Application of Noninvasive Vagal Nerve Stimulation to Stress-Related Psychiatric Disorders. Journal of Personalized Medicine, 10(3), p.119. https://doi.org/10.3390/jpm10030119
- Bravo, J. A., Julio-Pieper, M., Forsythe, P., Kunze, W., Dinan, T. G., Bienenstock, J., & Cryan, J. F. (2012). Communication between gastrointestinal bacteria and the nervous system. Current Opinion in Pharmacology, 12(6), 667-672.
- De Couck, M., Mravec, B., & Gidron, Y. (2012). You may need the vagus nerve to understand pathophysiology and to treat diseases. Clinical Science, 122(7), 323-328.
- Deutsch, S. I., Burket, J. A., & Benson, A. D. (2014). Targeting the α7 nicotinic acetylcholine receptor to prevent progressive dementia and improve cognition in adults with Down’s syndrome. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 54, 131-139.
- Frokjaer, J. B., Bergmann, S., Brock, C., Madzak, A., Farmer, A. D., Ellrich, J., & Drewes, A. M. (2016). Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity. Neurogastroenterology & Motility, 28(4), 592-598.
- Park, J. Y., & Namgung, U. (2018). Electroacupuncture therapy in inflammation regulation: current perspectives. Journal of Inflammation Research, 11, 227.
- Wu, C., Liu, P., Fu, H., Chen, W., Cui, S., Lu, L., & Tang, C. (2018). Transcutaneous auricular vagus nerve stimulation in treating major depressive disorder: A systematic review and meta-analysis. Medicine, 97(52)